I get how these attachments to the sole plate would set the distance between the block and the blade, but you’d still need a way to fasten board to something during the cut, and there is no surface to do that with since it’s only a 2x and therefore the circ saw sole plat will ride over the whole thing (can’t clamp it).

Well the previous post (some) were good but I just use a straight edge, clamp em down the skill saw will run right along. Similar to what wahoo posted but you can buy a set at lowes they work great. its not that complicated, unless you want it to be.

-- "Boy you could get more work done it you quit flapping your pie hole" Grandpa

Make a fence like the one waho609 posted above except make the cut off side exactly 3/8” narrower than the actual cut.

Place the stock to be cut against the side. The blade will take exactly 3/8” off. You need to add a stop on the end to keep the stock from sliding. And you will need a piece of flat stock to do dual duty: First to keep the bottom plate flat, and second to keep the stock firmly against the fence.

-- This post is a hand-crafted natural product. Slight variations in spelling and grammar should not be viewed as flaws or defects, but rather as an integral characteristic of the creative process.

I length and width of plywood that is bordered on all four edges with 1×2 guide rails might be worth considering to obtain straight rip cuts. The circular saw setting atop the plywood would be kept running true during the rip cut because the base plate of the saw would be captured by the bordering guide rail strips. By making this plywood jig long, the lumber to be ripped could be screwed or clamped to the underside of the jig at each end. Several pieces of double stick tape could also be used to keep the workpiece from shifting during the cut. Since the ripped workpieces are of a consistent width, a pair of stop blocks could be installed under the jig where the stop blocks are referenced off the saw kerf in the jig to yield the proper width.

Making the jig is straight forward except when aligning the second long guide rail. If the second guide rail is not positioned correctly the saw could bind or wonder when riding in the frame. One way to get an exact fit is to place the saw firmly against one or two thicknesses of printer paper sandwiched between the already secured long rail and the edge of the base plate of the saw (with the blade retracted). The second parallel guide rail is then brought into contact with the saw’s opposite base plate edge. The second guide rail is then clamped and screwed into place. The saw can be advanced about 9” and the process repeated. Waxing the base plate of the saw and its edges and the jig would allow the saw to slide smoothly down the length of the jig. After the end rails are installed, a plunge cut through the plywood base of the jig would produce the kerf.